The Worcester Salt Company series contain materials dating from 1839 to 2012 that are similar material to the location series above, but due to the large quantity of information on these topics, as well as the fact that many of these companies are or were national or even international, have warranted their own series. Each series is organized by subject, including business, correspondence, ephemera, images, publications, postcards, and films.

Those especially interested in ephemera may want to examine the collection of Worcester Salt Company coupons and paper dolls, used to sell salt. During the late 1800s and early 1900s containers of Worcester Salt came with coupons that could be collected and exchanged for merchandise. Within this collection is a sampling of these coupons, as well as booklets that include what coupons could be exchanged for. Worcester Salt also included collectable paper dolls in their salt containers to encourage customers to buy more salt. This series contains forty-nine of these paper dolls.